سطح فعاليت پروتيين هاي ضد انعقادي طبيعي پلاسما در كودكان مبتلا به تالاسمي ماژور

Natural anticoagulant system in children with beta-thalassemia major

Background and Objectives Thrombotic events are among the most important complications in patients with beta-thalassemia major. Alterations in natural anticoagulation system have a major contribution to the occurrence of thrombotic events in these patients. This study was performed to evaluate the protein C, protein S and Antithrombin III activity in patients with beta-thalassemia major having referred to Mofid Children Hospital in 1382. Materials and Methods Thalassemic children older than 2 years of age, with the interval of more than 25 days since last transfusion, and without any evidence of symptomatic liver or heart disease were enrolled in the study. Plasma activity of protein C and protein S was assessed by PTT based tests and the activity of antithrombin III was determined by chromogenic method. The correlation between decreased levels of anticoagulants and other parameters such as splenectomy, liver transaminases and serum ferritin level was analyzed by spss software. T-test and Mann whitney U-test were used to compare the mean values of variables. Results 20.3% of patients showed a decrease in protein C and 15.3% in protein S. 12 patients had been splenectomized. Mean protein C activity in splenectomized and non-splenectomized patients were 63.4 ± 17.9% and 74.5± 15.1% , respectively (p<0.04). Conclusions There was a decrease in proteins C and S activity in thalassemia major patients. Splenectomy might cause reduction in protein C level. Analytic studies are recommended to evaluate the activity of anticoagulant system in thalassemic patients. In addition, assessment of this system is suggested prior and after splenectomy .